scholarly journals In-situ rock tests for fault gouge zone：A case in Fengman hydropower station, China

2021 ◽  
Vol 293 ◽  
pp. 03008
Author(s):  
Xinchuan Xu ◽  
Zhaoyue Yu ◽  
Fangfang Xue ◽  
Xiaogang Long ◽  
Xinyu Mao ◽  
...  
Keyword(s):  
Large Scale ◽  
Scientific Basis ◽  
Test Point ◽  
Actual Condition ◽  
Hydropower Station ◽  
Bearing Plate ◽  
Dam Site ◽  
Fault Gouges ◽  
The Stability

The existence of faults in the dam site area threatens the stability and safety of large-scale hydropower projects in China. The fault argillaceous zone is the worst kind of fault fracture zone, and the determination of its deformation and strength parameters is the key point of rock engineering investigation. In this study, the in-situ bearing plate test and direct shear test were carried out on the gouge zone of F67 fault in the dam site of Fengman Hydropower Station. The test results show that the deformation and shear law of each test point is good, which is basically consistent with the actual condition of the measured rock mass. However, due to the limited number of measurements, the results are limited in terms of macroscopic representation. The experimental results provide scientific basis for subsequent engineering design and further enhance the understanding of mechanical properties of fault gouges.

scholarly journals Evaluating shear mobilization in rockfill columns used for riverbank stabilization

2009 ◽  
Vol 46 (8) ◽  
pp. 976-986 ◽  
Author(s):  
Marolo C. Alfaro ◽  
James A. Blatz ◽  
Wisam F. Abdulrazaq ◽  
Chang-Seok Kim
Keyword(s):  
Large Scale ◽  
Experimental Testing ◽  
Test Results ◽  
Lake Agassiz ◽  
Shearing Resistance ◽  
Glacial Lake Agassiz ◽  
The Stability ◽  
Rockfill Columns ◽  
The City

The major rivers within the City of Winnipeg are founded in glacial Lake Agassiz clay and silt sediments that have low shear strength. As such, riverbank instabilities are a common issue along many stretches of the rivers. The use of rockfill columns has become an increasingly utilized approach for stabilizing failing banks. Recent cases in Winnipeg have shown that movements can occur following installation of rockfill columns. Uncertainty regarding the magnitude of these movements that is required to mobilize shearing resistance in the rockfill columns has resulted in situations where the stability of riverbanks following remediation has been questioned. This has provided a need to improve our understanding about how much movement a stabilized slope must undergo before sufficient shear resistance of the rockfill column will be mobilized. The results of experimental testing conducted to assess the shear mobilization of rockfill column materials using a large-scale direct shear test apparatus are presented in this paper. The testing methodology is described along with the test results. The results show that the development of material specifications, construction, and placement methods and appropriate methods of analysis requires understanding of the stress–strain properties of the in situ soil and the rockfill material.

scholarly journals A chemo-enzymatic oxidation cascade to activate C–H bonds with in situ generated H2O2

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Simon J. Freakley ◽  
Svenja Kochius ◽  
Jacqueline van Marwijk ◽  
Caryn Fenner ◽  
Richard J. Lewis ◽  
...  
Keyword(s):  
Palladium Nanoparticles ◽  
Large Scale ◽  
Reaction Vessel ◽  
Enzymatic Oxidation ◽  
Catalytic Systems ◽  
In Situ Generation ◽  
Temperature And Pressure ◽  
The Stability ◽  
By Products

Abstract Continuous low-level supply or in situ generation of hydrogen peroxide (H2O2) is essential for the stability of unspecific peroxygenases, which are deemed ideal biocatalysts for the selective activation of C–H bonds. To envisage potential large scale applications of combined catalytic systems the reactions need to be simple, efficient and produce minimal by-products. We show that gold-palladium nanoparticles supported on TiO2 or carbon have sufficient activity at ambient temperature and pressure to generate H2O2 from H2 and O2 and supply the oxidant to the engineered unspecific heme-thiolate peroxygenase PaDa-I. This tandem catalyst combination facilitates efficient oxidation of a range of C-H bonds to hydroxylated products in one reaction vessel with only water as a by-product under conditions that could be easily scaled.

Numerical Back Inversion Method of Compressive Creep Parameters of Rock Masses under Rigid Bearing Plate and its Application

2008 ◽  
Vol 33-37 ◽  
pp. 429-434 ◽  
Author(s):  
Wen Dong Yang ◽  
Qiang Yong Zhang ◽  
Jian Guo Zhang
Keyword(s):  
Back Analysis ◽  
In Situ Monitoring ◽  
Inversion Method ◽  
Rock Masses ◽  
Creep Tests ◽  
Compressive Creep ◽  
Bearing Plate ◽  
In Situ Conditions ◽  
Dam Site

Due to lots of hypothesis, the theoretical analytical solution of the creep parameters inversion can not reflect the in-situ conditions actually. In order to simulate the process of the compressive creep tests of the in-situ bearing plate, the affection of the stratum distribution and the influence of the geological status in site actually, FLAC3D is used and numerical back analysis method of the creep parameters at dam site is set up. Based on the in-situ compressive creep tests’ data of the diabase rock masses at Dagangshan dam site, creep parameters are got with this method. Results indicate that the numerical calculated displacements of the compressive creep are similar to the in-situ monitoring displacements. It reveals that with this numerical method creep parameters can be backing analyzed logically. This supplies technical assurances to stability estimate and analysis of rock masses in slope projects.

The Stability Research and Evaluation of Jiuzi Collapse Accumulation

2012 ◽  
Vol 446-449 ◽  
pp. 2007-2010
Author(s):  
Ke Wang ◽  
Chang Ming Wang ◽  
Cen Cen Niu ◽  
Dong He Ma ◽  
Rong Lin
Keyword(s):  
Yunnan Province ◽  
Estimation Method ◽  
Assessment Method ◽  
Hydropower Station ◽  
Left Bank ◽  
Probability Assessment ◽  
Engineering Construction ◽  
Moment Estimation ◽  
Dam Site ◽  
The Stability

Collapse accumulation is one of the most common bad geology bodies in mountain and canyon regions in southwest of China. Jiuzi collapse accumulation, which is located in the left bank of 400~1200 meters from wanjiakouzi hydropower station in the Xuanwei city Yunnan province, is primarily performing as a collapse body with some sliding character. Due to the close location to the dam site, Jiuzi collapse accumulation shows a tremendous safe hidden trouble to the engineering construction, and studying on its stabilization is of prime importance. Taking Jiuzi collapse accumulation as an example, expound the application of the Rosenblueth moment estimation method into probabilistic analysis of slope stability, effectively combined the traditional safety factor method with probability assessment method.

Application of Damage Rheology Model in Study on an Underground Cavern Group

2011 ◽  
Vol 90-93 ◽  
pp. 760-763
Author(s):  
Yin Ping Qi ◽  
Lv Xiang ◽  
Wei Shen Zhu
Keyword(s):  
Large Scale ◽  
Southwest China ◽  
Back Analysis ◽  
Great Depth ◽  
Underground Cavern ◽  
In Situ Stresses ◽  
The Stability ◽  
Damage Rheology ◽  
Hydropower Stations

A great number of large-scale hydropower stations are to be constructed in southwest China. Many of them feature great depth or high in situ stresses. In this paper, a coupled damage and rheology method is adopted for stability analysis of an underground cavern group with time effect to consider the rock deformation. Meanwhile, a new method considering the crackopening displacement is used for back analysis. The stability of the surrounding rock masses is then evaluated.

Relation of Textural Stress and Rock Failure of Diversion Tunnel

2011 ◽  
Vol 243-249 ◽  
pp. 3685-3688
Author(s):  
Rui Gao
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Stress Field ◽  
Multivariate Regression ◽  
Large Scale ◽  
Regression Method ◽  
Rock Failure ◽  
Hydropower Station ◽  
Diversion Tunnel ◽  
The Stability

The textural stress has great effect on the stability of rock. According to the measured geo-stress data, through FEM and combined with the linear multivariate regression method, the geo-stress field was conducted. Using these methods, a diversion tunnel of a large-scale hydropower station was analyzed to study the stress distribution. It was shown that the stress concentration was located at the bottom of the wall and the arch top, the stress in the wall was little and the failure happened at the bottom of the wall and the arch top, then the bottom board and some areas far from the tunnel. Under the condition without considering textural stress, the stress concentration area located in the wall and the failure happened at the bottom of the wall, then in the middle of the wall and at the arch top.

scholarly journals Stabilisation of river dykes with drainage elements

2009 ◽  
Vol 9 (6) ◽  
pp. 2039-2047 ◽  
Author(s):  
T. Riegger ◽  
A. Bieberstein ◽  
F. Hörtkorn ◽  
H.-G. Kempfert
Keyword(s):  
Meteorological Conditions ◽  
Scale Model ◽  
Actual Condition ◽  
Ministry Of Education ◽  
Short Term ◽  
The World ◽  
River Flood ◽  
The Stability ◽  
Natural Scale

Abstract. In recent times, enormous damage has been caused by dyke failures during and after river flood disasters throughout the world. Besides extreme meteorological conditions the reasons for these failures are inadequate design and the actual condition of affected dyke structures. To minimize the occurrence of dyke failures in future, in a national BMBF research project (BMBF: German Federal Ministry of Education and Research) an alternative stabilisation technique has been investigated as an instrument for short term refurbishment and as an improvement to existing and endangered dyke structures. It is intended to improve the stability of dyke structures by the mechanical installation of drainage devices, thus preventing dyke failure by controlling the seepage in the structure. Within the scope of this paper selected results concerning stabilizing capability and feasibility of the stabilisation technique are presented in detail. Concerning feasibility the focus is placed on natural scale model tests to verify numerical calculations and to investigate the suitability of the adapted installation methods in situ.

In situ seepage testing method for fractured zones of rock mass

2020 ◽  
Vol 54 (1) ◽  
pp. qjegh2020-050
Author(s):  
Sihong Liu ◽  
Siyuan Xu ◽  
Bin Zhou
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Surrounding Rock ◽  
Hydropower Station ◽  
Permeability Characteristics ◽  
Critical Hydraulic Gradient ◽  
Testing Method ◽  
Natural Stress ◽  
Stress States

The permeability characteristics of rock mass discontinuities are important in the stability of hydropower station projects. We propose a large-scale in situ seepage testing method and use this method to test gently dipping bedding faults (C3 zone) and steep faults (F14) in a hydropower station construction field in China. The in situ test results are compared with those of both undisturbed and reconstituted specimens. The comparison indicates that the largest critical hydraulic gradient and the smallest seepage permeability coefficient are obtained via in situ tests because they are performed under stress states that simulate the natural stress of the surrounding rock mass. The natural stress of the surrounding rock mass cannot be reflected in tests of undisturbed and reconstituted specimens.

The Stability of a Rock Dam Site under Seismic Conditions

2011 ◽  
Vol 94-96 ◽  
pp. 1848-1857
Author(s):  
Jin Hu ◽  
Xue Zhi Yang ◽  
Yong Zhang ◽  
Jun Ye Zhong
Keyword(s):  
Rock Mass ◽  
Large Scale ◽  
Yellow River ◽  
Seismic Intensity ◽  
Rock Mass Structure ◽  
Seismic Acceleration ◽  
Dam Foundation ◽  
Dam Site ◽  
The Stability ◽  
The Right

This paper takes the Daliushu Dam Site in Yellow River as an example, which is located near the active fault zone with high seismic intensity. It studies the seepage of dam abutment rock mass in meizoseismal area and the stability under earthquake condition. The assessments on the key engineering problems of this project are based upon a large number of investigations, in-situ and laboratory tests, etc., which are carried out in the field by the author. We know that the "5∙12" Wenchuan Earthquake in 2008 triggered strong ruptures and damages of massif, and destructed the concrete facing of the Zipinpu rock-fill dam in Minjiang River, which is very close to the earthquake source and sufferd a 0.56g' seismic acceleration. For this reason, this paper analyzes the possible damage on the Daliushu Dam site rock mass under the grouting in the future earthquake, returning to the present poor quality condition of rock mass, while this dam shares the seismic intensity, seismic acceleration, dam type and dam height similar to the Zipinpu Project. This paper puts forward a new research thought, which is the longtime -lasting strong earthquake,first causes the rupture of rock mass and the decrease of rock mass mechani cal parameters, and the lasting earthquake will then worsen the rock mass structure mechanics parameters, and even cause the large-scale massif damage. From this viewpoint, this paper, analyzes the stability of the dam foundation and abutment rock mass especially the stability of the thin massif of the right dam abutment by the numerical analysis. The analysis show that under the normal and the earthquake conditions (excluding the rock mass damage and mechanical parameters decrese resulted from the lasting earthquake), The Daliushu Dam Site and the right dam abutment are still stable when the safety factor is assumed to be 0.802 under the lasting earthquake. In addition, the calculation results show that the stability is not enough.

A Study on Improving Methods of Multi-Source and Multipath in Large-Scale Examination System Cloud Environment

2014 ◽  
Vol 687-691 ◽  
pp. 2722-2727
Author(s):  
Cheng Yong Yang ◽  
Zhen Yu Li ◽  
Yue Dong Gu ◽  
Hua Fan
Keyword(s):  
Data Transmission ◽  
Large Scale ◽  
Actual Condition ◽  
Network Congestion ◽  
Cloud Environment ◽  
Examination System ◽  
Public Network ◽  
The Public ◽  
The Stability ◽  
Network Channel

With the enlargement of the test scale, the examination system has become the direction of large-scale. Large-scale examination system has advantage over the calculation in a cloud environment. But more candidates and examinations lead to network congestion. On the solutions of network congestion, there has been a lot of wan processing methods. But they are not suitable for application to run in the LAN's examination system according to actual condition. Therefore, this paper will introduce an improved method of multi-source multipath to alleviate the burden to the public network channel in the process of network data transmission. In order to improve the stability of the system by optimizing software to reduce the dependence on hardware. In the end, this paper will discuss the performance of this strategy.

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